3. Different classification of blood groups
There are 30 blood group containing 400 antigens.
Many of which contain cold antibodies that do not react at body
temperature.
The antigens that are involved in blood groups are called
agglutination and the antibodies are called agglutinins
Clinically important blood groups are.
ABO system
Rh system
MN system ,and others.
4. AIM:
The main purpose of conducting this experiment is to
understand the basic concept of the ABO blood group system
and to know our blood group and type.
9. Procedure:
➧ Take a clean glass slide with three depressions on it.
➧ Take the Monoclonal Antibodies (MAB) kit.
➧ Mark the three depression A,B and Rh
➧ In the first depression add Anti-A, to the second add Anti-B and
to the third add Anti-D
➧ Keep the slide aside safely without disturbing.
➧ Now wipe the ring finger of left hand or nondominant hand with
the alcohol swabs and rub gently near the fingertip, where the
blood sample will be collected.
10. ➧ Prick the ring fingertip with the lancet and wipe off the first
drop of the blood.
➧ As blood starts oozing out, allow it to fall on the three
depressions of the glass slide by gently pressing the fingertip.
➧ Apply pressure on the site where it was pricked and to stop
blood flow. Use the cotton ball if required.
➧ Mix the blood sample gently with the help of separate
toothpicks and wait for a minute.
➧ observe the result.
➧ Can also use microscope to confirm the presence or absence of
clumping of blood.
11.
12.
13.
14. Crossmatching
➢ It is a procedure performed prior to transfusion of blood or blood
products to detect any serological incompatibilities in the blood of
donor and recipient.
➢ Before a donor’s blood is transfused into a recipient, there should
be no antigens or antibodies in both, that would react with each
other resulting in transfusion reaction.
➢ Cross matching is designed to prevent such transfusion reactions
which may occur after transfusion.
15. Crossmatching
Significance:
➢ Know how recipient body will react to those donor blood.
Routine blood grouping involves only ABO and Rh .
➢ Other clinically significant blood group systems not matched
routinely.
➢ Though antibodies to donor antigens are of rare occurrence, can
cause transfusion reactions.
➢ Cross matching between patient’s serum and donor’s cells will
detect antibodies to other blood groups,
➢ If present help to prevent blood transfusion reactions.
16. Types:
➔ Major cross match:
A procedure used to determine compatibility between RBCs of the
donor and the serum (plasma) of the recipient.
➔ Minor crossmatch:
A procedure used to determine compatibility between the serum
(plasma) of the donor and the RBCs of the recipient.This test is no
longer used routinely but has historical significance.
19. The test to work out which part of the ABO blood group a person is in
is known as the ABO blood typing which involves two steps
1) Forward typing:
A blood sample is tested against 2 solutions in a lab. - one with
antibodies against the A antigen (Anti-A) and one that has an antibody
against the B antigen (Anti-B). The way blood reacts to antibodies is
an indicator of which type of antigens are present in the blood. If you
have the A antigen (blood group A) when the anti-A antibodies are
added, the blood cells will clump together in a process called
agglutinating. If it doesn't react for both, it must be the O-type.
20. 2)Reverse typing:
In this step, the plasma (the fluid part of the blood after the WBC
and RBCs have been removed) and this is mixed with the type A
blood first and then separately with type B to check the reaction.
Whether the agglutination takes place or not should be an indicator
to confirm the forward typing results. Both types must agree on the
same blood type.
21. Rhesus typing:
This is another type of test which can help determine the type of
Rhesus blood type. In this test, a small sample of the RBC is mixed
with a lab solution containing the antibodies to the RhD. If the
blood reacts to the Rh test with agglutinating, it is called Rh
positive and if it doesn't, it is Rh Negative.
Both the ABO and the RhD blood typing process are done all the
blood collected from donors and for blood used for the transfusions
in major hospitals. On occasion, testing is needed for the other red
cell antigens, mostly in people who have rare disorders.
22. Results and Interpretation
Compatible donor and recipient blood should show no agglutination in
both major and minor cross match.
Blood which shows incompatibility in major cross match should never
be transfused, because the large plasma volume of the recipient blood
containing antibodies can destroy the donor’s red cells easily.
The minor incompatibility is less important because the donor’s serum
which contains the antibodies is diluted in the recipient’s own plasma,
making the antibodies very dilute and ineffective.
